Methods and systems for protecting website forms from automated access

A method for selectively accepting access requests from a client computer connected to a server computer by a network, the method comprising:

• receiving an access request from the client computer at an authentication server;
• the authentication server generating a matrix of non-overlapping images in response to the access request, wherein the matrix of non-overlapping images comprises at least one randomly selected image from a randomly selected image category chosen for an image recognition task and at least one image not from the randomly selected image category, wherein the image recognition task comprises an instruction to select one image corresponding to the selected image category from the matrix of non-overlapping randomly selected images;
• presenting the dynamic graphical arrangement of images on an output device of the client computer;
• receiving an input from the client computer at the authentication server, the input comprising a user selection of at least one image;
• the authentication server accepting the access request if the user selection of the at least one image corresponds to the image chosen from the selected image category and otherwise denying the access request;
• and
• wherein the matrix comprises at least one image known to belong to the selected image category, at least one image known to not belong to the selected image category and at least one image suspected to belong to the selected image category and wherein the user is still granted access to the website when the input from the user access device comprises selection of the at least one image known to belong to the selected image category and selection or omission of the at least one image suspected to belong to the selected image category.